Dotan Cohen wrote:
Oleg, I understood that the universe has 11 or so dimensions, and that
5 or six can even be measured. But the wikipedia article that you link
to claims only 3+1. I have googled a bit but found only very technical
explanations, or baby facts with no explanations. Can you sum it up
for someone who is familiar with relativity, but is not a physicist?
Thanks.
I'll do my best as another non-physicist, and then Oleg (or anyone else)
can correct me where I'm wrong.
In an attempt to create a grand unified theory(tm) of everything (and
rejecting, with no explanation, the answer "42"), some physicists have
tried the "big hammer"(tm) approach - i.e. - hammer on the equations
until they fit. This method is not to be put down, as it allowed Lorentz
to phrase his Lorentz transformation even before Einstein came around
and provided a relatively simple (excuse my pun) explanation for the "why".
In particular, the modern hammerists came up with "strings theory". It
is an extrapolation of existing theories, designed to encapsulate all
known to be somewhat true theories about the universe (in particular,
general relativity on the one hand, and quantum mechanics on the other).
Strings theory does, indeed, claim that the universe has 12 dimensions.
Here's the catch. Strings theory is so generic, that it fails to supply
one of the basic requirements of any scientific theory. It fails to
provide predictability. Any scientific theory must come with an
experiment that is possible to perform (at least theoretically), with
certain outcomes being agreed to mean that the theory is disproved. If a
theory cannot supply such an experiment, it means that any possible
outcome of any possible experiment is okay with that theory, and this
means it lacks any ability to actually predict the outcome of yet
unperformed experiments. Such a theory may be fine for philosophers, but
is useless to scientists, and in particular, to physicists.
And yet, it seems that strings theory is very far from useless. Strings
theory has garnered support, and more importantly, research grants, and
have occupied the time of our bests physicists around the world, with
nothing concrete to show for it but the money well spent. It is trendy,
and has been for quite some time now, but, at least as far as I'm
concerned (and unless I am totally misunderstanding the situation, which
is possible), it is not physics. People like it because of its
potential, but this potential, after over a decade of research, has
failed to materialize into something you can try and disprove.
Shachar
--
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
http://www.lingnu.com
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